There is known a radiator through which a coolant flows. The radiator includes two tanks and plural tubes connecting the tanks with each other. A technology relating to the radiator is disclosed in Japanese Unexamined Patent Application Publication No. 2007-192441.
The plural tubes are arranged to be aligned. In light of the heat radiation efficiency, it is preferable to provide such plural tubes. This is because the ensuring of the whole length of the tubes improves the heat radiation efficiency. However, the provision of plural tubes increases the size of the radiator in such a direction as to align the tubes.